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