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