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