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