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