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)(27,32,36,31)(28,29,39,37)(34,40,38,35)(1,2,4,6)(3,5,8,7)(9,10)(11,15)(12,16)(13,14)(17,19)(18,23)(20,24)(21,22)(25,26,30,33)(27,32,36,31)(28,37,39,29)(34,35,38,40)(1,2)(3,5)(4,6)(7,8)(25,27,30,36)(26,31,33,32)(28,34,39,38)(29,35,37,40)(1,3,4,8)(2,5,6,7)(9,10)(11,17)(12,16)(13,14)(15,19)(18,24)(20,23)(21,22)(25,27)(26,32)(28,38)(29,35)(30,36)(31,33)(34,39)(37,40)(9,11,13,19)(10,15,14,17)(12,20,21,18)(16,24,22,23)(25,28,30,39)(26,29,33,37)(27,34,36,38)(31,35,32,40)(9,12,13,21)(10,16,14,22)(11,18,19,20)(15,23,17,24)(25,29)(26,28)(27,35)(30,37)(31,34)(32,38)(33,39)(36,40)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.