Dana Perino offers the cure to political sex scandals:
While I am not able to explain, I do think I know the answer to all of this: Elect more women. No woman I know has the time for such trysts, nor do I know any who say the desire one. They're too busy trying to keep all the plates spinning at home, at work, and at the gym to make sure none fall and break.
Let me chime in with a deep and heartfelt "Probably not." I think it's likely that a woman would like face a penalty in degree and kind that men don't. That probably serves as a deterrent. But it's not absolute. As Matt notes, there's a serious sample-size problem here.
I would suggest that the lack of sex scandals among women is more a marker of a kind of immaturity around women's issues in our politics. This nobler than thou approach is also a dangerous line of reasoning and (I hate to say this again) a kind of attack on the humanity of women.
I'd be very interested in how this has played in other countries where female politicians serve in greater numbers, and more prominent positions.