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