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