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