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