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