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