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