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