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