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