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