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