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