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