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