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