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