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