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