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