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