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