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