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