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