Dear __________,
Thank you so much for the graduation card and money. As most of my outfits consist of jeans, T-shirts and sweaters, I find my wardrobe greatly lacking in business attire. This week when I go shopping for a few outfits that are suitable for interviews, your practical and thoughtful gift will go a long way in helping me get a few more items that I could not otherwise afford. Thank you again.
(YOUR NAME HERE)