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