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