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