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