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