One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,6)(4,5)(7,8)(9,10,13,11)(12,15,16,14)(19,25)(20,28)(22,26)(24,31)(2,5)(6,8)(9,11,13,10)(12,15,16,14)(17,18)(19,26)(20,24)(21,23)(22,25)(27,32)(28,31)(29,30)(9,12,13,16)(10,14,11,15)(17,19)(18,22)(20,29)(21,25)(23,26)(24,32)(27,28)(30,31)(12,16)(14,15)(18,23)(19,25)(24,31)(27,29) involution — undirected(17,20,21,28)(18,24,23,31)(19,27,25,29)(22,30,26,32)(1,3,4,7)(2,6,5,8)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.