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