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