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