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