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