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