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