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