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