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