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