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