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