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