I think saying something like, "One aspect of sorority life that appeals to me is the opportunity for leadership development while I am in college." is completely appropriate.
That way it allows you to express your interest in that aspect of sorority membership but doesn't sound like you expect to be chapter president next fall.
If it feels appropriate during the flow of the conversation to turn it into a question, even better. Ask what kind of leadership development they have for their members. Or tie your interest into your major if that fits.
One thing to keep in mind is that leadership selection varies from group to group. Some groups do elections where people "run" for office. Other groups do selection by nominating committee and so running or jockeying for a specific office is a no-no. I doubt that this will come up and it isn't something you can ask about, but thought I would mention it.
I hope it goes well for you! Come back and share your story!
