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