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