One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,6)(4,5)(7,8)(9,10)(11,14)(12,13)(15,16)(17,18)(19,28)(20,32)(21,26)(22,27)(23,25)(24,31)(29,30) involution — undirected(2,5)(3,7)(17,18,22,27)(19,29,31,21)(20,25,23,32)(24,30,28,26)(10,13)(14,16)(17,19,20,30,22,31,23,26)(18,24,32,21,27,28,25,29)(2,5)(6,8)(9,11,12,15)(10,14,13,16)(17,20,22,23)(18,25,27,32)(19,30,31,26)(21,24,29,28)(1,3,4,7)(2,6,5,8)(17,21,23,24,22,29,20,28)(18,26,25,31,27,30,32,19)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.