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