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