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