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