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