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)(11,19)(12,22)(13,24)(14,18)(15,21)(16,23)(17,20)(25,26,29,32)(27,30,35,39)(28,31,36,40)(33,37,34,38)(1,3,5,8)(2,6,4,7)(9,11,14,21)(10,15,18,19)(12,20,23,13)(16,17,22,24)(25,27)(26,30)(28,34)(29,35)(31,38)(32,39)(33,36)(37,40)(9,12,14,23)(10,16,18,22)(11,13,21,20)(15,24,19,17)(25,28)(26,31)(27,33)(29,36)(30,37)(32,40)(34,35)(38,39)(1,2,5,4)(3,6,8,7)(9,12)(10,16)(11,20)(13,21)(14,23)(15,17)(18,22)(19,24)(25,26)(27,30)(28,31)(29,32)(33,37)(34,38)(35,39)(36,40)(1,2,5,4)(3,6,8,7)(9,13,14,20)(10,17,18,24)(11,12,21,23)(15,22,19,16)(25,28)(26,31)(27,34)(29,36)(30,38)(32,40)(33,35)(37,39)(1,4,5,2)(3,7,8,6)(9,10)(11,15)(12,16)(13,24)(14,18)(17,20)(19,21)(22,23)(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.