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