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