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