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)(11,19)(12,16)(13,17)(14,18)(15,21)(20,24)(22,23)(25,26,32,35)(27,36,31,30)(28,33,40,37)(29,38,39,34)(1,3,4,8)(2,5,6,7)(25,27,32,31)(26,30,35,36)(28,38,40,34)(29,37,39,33)(9,11,14,21)(10,15,18,19)(12,13,20,23)(16,22,24,17)(25,28)(26,33)(27,34)(29,36)(30,39)(31,38)(32,40)(35,37)(9,12,14,20)(10,16,18,24)(11,13,21,23)(15,22,19,17)(25,29,32,39)(26,34,35,38)(27,37,31,33)(28,36,40,30)(9,13)(10,17)(11,20)(12,21)(14,23)(15,16)(18,22)(19,24)(25,30,32,36)(26,27,35,31)(28,39,40,29)(33,34,37,38)(9,10)(11,15)(12,16)(13,22)(14,18)(17,23)(19,21)(20,24)(25,31,32,27)(26,30,35,36)(28,38,40,34)(29,33,39,37)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.