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