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)(25,26,29,32)(27,33,35,30)(28,31,36,38)(34,39,40,37)(2,5)(6,8)(9,10)(11,17)(12,14)(13,16)(15,19)(18,24)(20,22)(21,23)(25,27,29,35)(26,30,32,33)(28,34,36,40)(31,37,38,39)(1,2,4,5)(3,6,7,8)(10,12)(15,17)(16,20)(23,24)(25,27)(26,30)(28,34)(29,35)(31,37)(32,33)(36,40)(38,39)(3,7)(6,8)(9,11)(10,15)(12,17)(13,21)(14,19)(16,24)(18,22)(20,23)(25,27)(26,30)(28,34)(29,35)(31,37)(32,33)(36,40)(38,39) involution — undirected(1,2)(3,6)(4,5)(7,8)(9,12,14,10)(11,17,19,15)(13,20,22,16)(18,24,21,23)(25,26)(27,30)(28,31)(29,32)(33,35)(34,37)(36,38)(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)(25,28,29,36)(26,31,32,38)(27,34,35,40)(30,37,33,39)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.