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