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