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