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