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