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