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