In my final year I helped out on Open Days and Applicant Visit Days as a Student Ambassador for the English department and I can tell you it's very rewarding and you get paid.
I managed to get the part-time job by asking my course tutors about helping out and they directed me towards Unitemps which is a recruitment agency that helps students find part-time and temporary work. The Salford Unitemps branch can be found inside University House on campus a.k.a our Students' Union!