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