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