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