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