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