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