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