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