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