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