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