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