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