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