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