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