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