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