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