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