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