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