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