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