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