One vertex per element, one color per generator, with an edge from x to x·s.
(5,6)(7,13)(8,17)(9,19)(10,12)(11,16)(14,18)(15,20)(21,22)(23,25)(24,31)(26,30)(27,34)(28,32)(29,35)(33,36) involution — undirected(1,2)(3,4)(5,7,9,16,10,15,18,8)(6,11,14,13,12,17,19,20)(21,23,25,22)(24,29,33,27)(26,30,32,28)(31,34,36,35)(2,4)(6,12)(7,15)(8,16)(14,19)(21,24,32,35,25,33,26,34)(22,27,30,36,23,29,28,31)(5,8,18,15,10,16,9,7)(6,13,19,11,12,20,14,17)(22,23)(27,29)(28,30)(31,36)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.