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)(12,20,22,16)(18,23,21,24)(25,26,30,28)(27,31,33,34)(29,32,37,36)(35,38,39,40)(3,7)(6,8)(9,11,14,19)(10,15,13,17)(12,18,22,21)(16,23,20,24)(25,27)(26,31)(28,34)(29,35)(30,33)(32,38)(36,40)(37,39)(1,2)(3,6)(4,5)(7,8)(10,13)(15,17)(16,20)(23,24)(27,33)(31,34)(35,39)(38,40) involution — undirected(1,3,4,7)(2,6,5,8)(9,11)(10,15)(12,21)(13,17)(14,19)(16,24)(18,22)(20,23)(25,28,30,26)(27,34,33,31)(29,32,37,36)(35,38,39,40)(1,2)(3,6)(4,5)(7,8)(9,12)(10,16)(11,18)(13,20)(14,22)(15,23)(17,24)(19,21)(25,29)(26,32)(27,35)(28,36)(30,37)(31,38)(33,39)(34,40) involution — undirected(9,13,14,10)(11,17,19,15)(12,20,22,16)(18,24,21,23)(25,27)(26,31)(28,34)(29,35)(30,33)(32,38)(36,40)(37,39)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.