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