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