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