One vertex per element, one color per generator, with an edge from x to x·s.
(1,2) involution — undirected(3,4)(5,6)(7,8,12,16,13,17,11,26)(9,18,22,28,20,32,21,14)(10,15,24,29,25,30,23,36)(19,31,35,37,33,38,34,27)(4,6)(7,9)(8,14,17,28)(10,19)(11,21)(12,22)(13,20)(15,27,30,37)(16,18,26,32)(23,34)(24,35)(25,33)(29,31,36,38)(7,10,12,24,13,25,11,23)(8,15,16,29,17,30,26,36)(9,19,22,35,20,33,21,34)(14,27,18,31,28,37,32,38)(9,20)(14,28)(18,32)(19,33)(21,22)(27,37)(31,38)(34,35) involution — undirectedA 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.