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