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