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