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