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