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