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