The talented actress plays the title character in ''Life of the Party: The Pamela Harriman Story''

She doesn’t swivel her hips like she did in Viva Las Vegas. She doesn’t jiggle her middle like she did in Bye Bye Birdie. But sitting on a sofa in her Beverly Hills home, a silk scarf wrapped demurely around her flame red hair, Ann-Margret does occasionally break into song.

”This number just popped into my mind,” she offers before softly crooning, ”’I love to call you Rose, but roses fade away. I’d love to call you Honey…”’

And — go figure — she’s still got it. At 57, Ann-Margret may not be a kitten with a whip anymore, but she clearly remembers how to purr. Also how to scratch and claw her way to the top, at least judging by her new TV biopic, Life of the Party: The Pamela Harriman Story, in which the woman who inspired The Flintstones’ Ann-Margrock plays one of the most unlikely roles of her career: An English-born, social-climbing aristocrat who seduced (and frequently married) some of the world’s wealthiest, most powerful men (Winston Churchill’s son Randolph, Broadway producer Leland Hayward, New York Governor Averell Harriman).

”Men were fascinated by Pamela Harriman — and so were women,” says the actress (married to producer Roger Smith for 31 years). ”She could be intensely charming but also very calculating. She was really a women’s libber before her time. She was an Englishwoman who ended up the American ambassador to France [until her death in 1997]. She went through a lot of phases in her life.”

Ditto Ann-Margret. There was her sweet-but-seductive bombshell-next-door phase (State Fair); her year of Elvis (though she’s still keeping mum about their rumored romance); her lamented cheesy B-movie stage (”Kitten With a Whip started out much grittier, but the studio completely altered it”); her psychedelic period (”I got 27 stitches filming Tommy — I cut my hand on that broken TV set during ‘Champagne”’); as well as her brush with serious acting (winning an Oscar nod for Carnal Knowledge, followed by a very credible Blanche DuBois in a TV version of A Streetcar Named Desire). Not to mention her whirl as a Vegas headliner (briefly sidelined by an infamous fall during a concert in Lake Tahoe) and her recent big-screen comeback (the two Grumpy Old Men flicks).

And now her cable-TV movie phase. ”I just find Harriman fascinating,” she says. ”Once she knew what she wanted, she went after it. But she was completely different when she was with a man. And we wanted to show that in this movie — we wanted to show everything.” (Including an ice-cube trick Harriman supposedly performed on her husbands, so kinky it would impress a White House intern.)

”I was a little surprised when I heard Ann-Margret was playing Pamela,” admits Christopher Ogden, who wrote the 1994 best-seller on which the movie is based. ”But she really captured the cadence of her voice, her mannerisms. She even looks like her.”

This latest phase may last awhile: Ann-Margret’s next project will be Showtime’s Happy Face Murders, in which she plays a grandmother on trial for murder. Granny With a Whip. We can’t wait.