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