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