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