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)(25,26,31,33)(27,35,36,32)(28,38,37,34)(29,39,40,30)(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)(26,32)(28,30)(29,34)(31,36)(33,35)(37,39)(38,40) involution — undirected(1,3,5,4)(2,6,8,7)(10,14)(15,21)(16,19)(22,24)(26,33)(27,36)(28,37)(29,40)(9,11)(10,15)(12,18)(13,17)(14,21)(16,22)(19,24)(20,23)(25,28,31,37)(26,34,33,38)(27,30,36,39)(29,35,40,32)(1,4,5,3)(2,7,8,6)(9,10)(11,15)(12,19)(13,14)(16,20)(17,21)(18,24)(22,23)(25,29,31,40)(26,30,33,39)(27,34,36,38)(28,35,37,32)(9,12,13,20)(10,16,14,19)(11,18,17,23)(15,22,21,24)(25,30)(26,29)(27,37)(28,36)(31,39)(32,38)(33,40)(34,35)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.