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