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