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