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