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