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