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