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