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