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