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