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