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