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