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