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)(26,31)(27,28)(32,35)(36,38)(9,11,14,21)(10,15,17,19)(12,20,13,22)(16,23,18,24)(25,26)(27,33)(28,37)(29,31)(30,32)(34,36)(35,39)(38,40)(2,6)(7,8)(9,12,14,13)(10,16,17,18)(11,20,21,22)(15,23,19,24)(26,32)(27,28)(30,39)(31,35)(33,40)(34,37)(1,3,5,4)(2,7,6,8)(10,17)(15,19)(16,18)(23,24)(25,27,29,28)(26,33,31,37)(30,36,39,38)(32,34,35,40)(1,4,5,3)(2,8,6,7)(9,13,14,12)(10,18,17,16)(11,20,21,22)(15,23,19,24)(25,28,29,27)(26,34,31,40)(30,36,39,38)(32,33,35,37)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.