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