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