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