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