Hi
As far as I can remember you need only to connect the + and - of the signal to all sensors in parallel. BUT some 485 require a terminating resistor. so it is better to check the documentation.
Also remember each sensor will have a unique address (but the same baudrate) and will require the 'host' to 'request' data. (Data polling) (Otherwise it will be chaos on the RX line if all sensors transmit simultaneously.) If you only use one the sensor might have a 'stream out' option so you just have to listen.
Adie