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)(11,22)(12,19)(13,24)(14,17)(15,20)(16,21)(18,23)(28,36)(33,38)(35,37)(39,40)(1,3,5,8)(2,6,4,7)(9,11)(10,15)(12,13)(14,23)(16,20)(17,24)(18,19)(21,22)(25,26,31,30)(27,34,29,32)(28,33,36,38)(35,40,37,39)(1,2,5,4)(3,6,8,7)(9,12,16,14)(10,17,21,19)(11,23,20,13)(15,18,22,24)(25,27,31,29)(26,32,30,34)(28,35,36,37)(33,39,38,40)(1,2,5,4)(3,6,8,7)(9,13,16,23)(10,18,21,24)(11,12,20,14)(15,19,22,17)(25,28,31,36)(26,33,30,38)(27,35,29,37)(32,39,34,40)(1,4,5,2)(3,7,8,6)(9,14,16,12)(10,19,21,17)(11,23,20,13)(15,18,22,24)(25,29,31,27)(26,32,30,34)(28,37,36,35)(33,39,38,40)(9,15,16,22)(10,20,21,11)(12,18,14,24)(13,19,23,17)(25,30,31,26)(27,34,29,32)(28,38,36,33)(35,40,37,39)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.