I personally think a 'Graduation Ball', something most universities have, is a good way to celebrate students finishing their studies from UoC. Fundraising can be done throughout the year to afford a venue, DJ, etc, and there could even be a Ball Comittee to ensure it runs smoothly, and to organise and plan. The general idea is a formal event, like a prom, for the leavers of the event to attend and celebrate. This really highlights home social ties with the university, a celebration of success, and something to look forward too.
Thanks!