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