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