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