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