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