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