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