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