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