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