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