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