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