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