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