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