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