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