What does one wear to a grad school inerview?

As the date of mygrad school interview approaches, the level of anxiety i've been experiencing has been tremendou. The main problem on my list of concerns is finding the perfect outfit that will send just the right message!
I'm going  for classy and chic, but not over the top. I do not want to the interviewer to think i've been shopping and obsessing over this outfit for weeks. Even though I have been.

All of these were takes from http://www.topshop.com/