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