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