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