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