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