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