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