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