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