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