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