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