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