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