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