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