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