Airplay to SONOS PLAY:1 WiFi speaker

I have a working Airport Express network which is also connected via wire to the local stereo. I can Airplay music from the iPad and IPhone perfectly. Now I want to add a wifi speaker on the patio to play the same Airplay stream. I bought a SONOS PLAY:1 speaker and it won't play the Airplay stream that is playing in the other room. Ii is connected to the network just fine and will accept a stream from the SONOS app, but not from Airplay. How do I get the SONOS speaker to play the same Airplay stream that is playing in the other room?