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