I'd gather you'll want to think fairly hard about scenarios you have encountered in the past where you helped a team you were on through a rough patch, or helped ship a product on time, or pull people together. You'll probably also want to have some sort of hypothesis about what makes a successful manager, what makes for a successful team, how to deal with failure, etc. If you haven't though about these things or are not interested then you may not enjoy management.

Edit: I would also come ready with any sort of anecdotes about how you took initiative to do something and managed it end to end. Could be an event, could be a product, could be a code release - but that track record is definitely an indicator.