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)(11,23)(12,30)(13,20)(14,17)(15,22)(16,21)(18,27)(19,33)(24,36)(25,37)(26,29)(28,35)(31,32)(34,39)(38,40) involution — undirected(2,5)(6,8)(9,11,15,27,17,29,16,28)(10,18,21,23,14,35,22,26)(12,25,32,24,13,34,33,40)(19,37,20,38,31,39,30,36)(1,3,4,7)(2,6,5,8)(9,12,15,32,17,13,16,33)(10,19,21,20,14,31,22,30)(11,24,27,34,29,40,28,25)(18,36,23,37,35,38,26,39)(9,13,17,12)(10,20,14,30)(11,25,29,34)(15,33,16,32)(18,36,35,38)(19,21,31,22)(23,37,26,39)(24,28,40,27)(9,14)(10,17)(11,26)(12,31)(13,19)(15,22)(16,21)(18,27)(20,33)(23,29)(24,39)(25,38)(28,35)(30,32)(34,36)(37,40) 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.