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