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