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