How old is she?
Often rabbits will dig at your clothes in an attempt to get at your skin. She can't properly groom you if she can't get to your skin. Silly human, what is all that fabric stuff in the way?
It's her attempt to communicate something with you. It's your job to figure out what that is exactly. It could be her wanting to lick your skin like blue eyes mentioned, or she might be trying to get your attention for petting her, or moving out of her way, or feeding her, or she may just like rearranging fabric(lots of rabbits do). If my rabbit is trying to get my attention I just start going through the list of possible reasons until I hit on the right one. Try letting her lick your hand, if not that then try giving head rubs, if not that then try moving out of her way or gently move her out of your way(you should be the top bun after all), if not that then try giving her a fleece blanket she can rearrange and play with.
Since rabbits can't really make noises, they only have certain ways to communicate with us and digging at us can be one of them. If you don't want her to do it then you need to redirect her behavior to something else and reward the behavior that you want from her. So basically if she nose bumps you for attention, reward that, but if she digs at you move her away from you gently with your hand and redirect her to something else, then reward the good behavior. http://language.rabbitspeak.com/