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