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