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