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