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