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