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