Can't. The 4067 is like a single deck rotary switch.
16 to 1 or 1 to 16.
You would need two chips to switch A+ and A-
There are other chips in that family, like the HC4052 (two decks).
But I think OP is trying to use your HX711 boards, not more load cells connected to one board.
In which case he doesn't need a muxer.
Leo..