When sending out the cash to the graduates on your list, why not also give them a book?  You've heard those grim statistics about the high percentage of college students losing their faith, so why not plant a small seed.  More importantly let the graduate know that you will pray for them--and do so at your next rosary.  Here are some great book suggestions to get you started.  (Just Google the title, or better yet, purchase at your local Catholic book store)

Letters to a Young Catholic--George Weigel
Magnificat Gift Subcription
Disorientation: How to Go to College Without Losing Your MInd
The New Catholic Answer Bible
Youcat
Here. Now. A Catholic Guide to the Good Life
Blessed are the Bored in Spirit
Rediscovering Catholicism
Be a Man: Becoming the Man God Meant You to Be
The Notre Dame Prayer Book
A Teen's Game Plan for Life--by Lou Holtz (famous Football coach)
Ready for College--Michael Pennock
Holy Goals for Body and Soul--(for sports enthusiasts)
Moving Forward: Staying Catholic in College (from Lifeteen)
Your CollegeFaith Own It--by Matt and Colleen Swaim

Also check out the books at DynamicCatholic.com. They have many great titles that you can buy pretty inexpensively in bulk. You can get 6 books for the price of 1 or 2.

Other suggestions I have gotten:
The Young Man's Guide: Counsels, Reflections and Prayers for Catholic Young Men By Rev. Francis Xavier Lasance 

The Catholic Girl's Guide: Counsels & Devotions for Girls in the Ordinary Walks of Life by Rev. Francis Xavier Lasance ​

​Finding True Happiness (& other books in series) by Robert J. Spitzer, S.J.

When Breath Becomes Air by Paul Kalanithi

Before I Go: Letters to Our Children About What Really Matters by Peter Kreeft

Purity of Heart is to Will One Thing by Soren Kieerkegard