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