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