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