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