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