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