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