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