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