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