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