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