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