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