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