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