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