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