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