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