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