If you're in the smooth preview (3 on the keyboard) Select your mesh:

Modify > Convert > Smooth Mesh Preview to Polygons

Then, just adjust the settings as needed in the channelbox for the polySmothFace node.

Otherwise, you could just use:

Mesh > Smooth

Just be aware that too much smoothing may slow down your modeling so save it for the end and just use the 3 key to preview. If you want to actually have a a smoothed version and poly side-by-side and on separate layers, you could read up on using Maya's poly proxy.