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