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