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