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