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