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