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)(9,17)(10,14)(11,24)(12,15)(13,20)(16,27)(18,35)(19,33)(21,38)(22,34)(23,31)(25,29)(26,32)(28,37)(30,36) involution — undirected(7,9,12,19)(8,13,15,29)(10,21,23,37)(11,25,27,20)(14,30,31,35)(16,33,24,17)(18,26,36,22)(28,34,38,32)(4,6)(7,8)(9,13)(10,14)(11,16)(12,15)(17,20)(18,28)(19,29)(21,30)(22,32)(23,31)(24,27)(25,33)(26,34)(35,37)(36,38) involution — undirected(7,10,12,23)(8,14,15,31)(9,18,19,36)(11,26,27,22)(13,28,29,38)(16,34,24,32)(17,35,33,30)(20,37,25,21)(8,15)(9,19)(14,31)(16,24)(18,36)(20,25)(21,37)(32,34) 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.