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