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