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