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