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