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