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