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