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