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