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