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