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