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