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