How to identify the right bus

My hotel will be in Praiano. My bus stop has a Fermata Sita sign with a bus icon. It also has a blue sign with the number 12 and Marina di Praia. I think the Sita sign is the bus that will take me to Amalfi. The 12 sign is the local if I want to work back to Positano stopping at local stops. Please correct me if I’m wrong. My question is how do I identify which bus to take. Are they different colored buses? Is there a sign on the front of the bus above the driver? Thanks for your help.