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