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