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