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