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