It depends on many variables (that we don't know of). Age of the bus kids, the street you live on, distance from your street to your front door, do you have a large window with clear view of the bus.

I used to work for a family with 4 kids. They lived on a very short, small one way street. Since the bus fully blocked the road there was no chance of a car passing the bus and no oncoming traffic. Also, the front of house was only about 15feet from the street (no front yards). I was able to read on the couch with the other kids and wave to the driver when they stopped. the driver could ensure I was home and the bus child would come running in. In this situation it was perfectly fine to not be outside on the street waiting. But, in most cases I think you'd likely have to be outside.

What ever you do, make sure all parents of your daycare are aware of what is going on.