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