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