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