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