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