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