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