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