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