One vertex per element, one color per generator, with an edge from x to x·s.
(1,2,5,7,6,3,4,8)(9,10)(11,21)(12,26,30,17)(13,20)(14,18)(15,19)(16,23)(22,37,39,34)(24,32)(25,33)(27,40,38,31)(28,35,29,36)(1,3,6,2)(4,7,5,8)(9,11,15,25)(10,16,19,32)(12,27,30,38)(13,24,14,23)(17,34,26,37)(18,33,20,21)(22,28,39,29)(31,35,40,36)(9,12)(10,17)(11,22)(13,29)(14,28)(15,30)(16,31)(18,36)(19,26)(20,35)(21,34)(23,27)(24,38)(25,39)(32,40)(33,37) 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.