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