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