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