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