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