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