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