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