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