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