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