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