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