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