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