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)(11,15)(12,14)(13,16)(19,28)(21,31)(23,30)(25,32) involution — undirected(9,11)(10,13)(12,16)(14,15)(17,18,22,26)(19,21,28,31)(20,24,29,27)(23,32,30,25)(2,5)(6,8)(11,16)(13,15)(17,19,29,32,22,28,20,25)(18,23,24,31,26,30,27,21)(1,3,4,7)(2,6,5,8)(10,14)(13,15)(17,20,22,29)(18,24,26,27)(19,25,28,32)(21,23,31,30)(17,21,29,23,22,31,20,30)(18,25,24,19,26,32,27,28)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.