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