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