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