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