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