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