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