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