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