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