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