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