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