Do you mean the CPU meter within the transport window, or the free floating CPU meter
If the latter, simply double click on the cpu meter in the transport
to open it as a window - or assign a key command to it, if you haven't already. Or open it
from Options -> Audio -> System Performance.
If the former, right-click
on the transport, select "Customise transport" and make sure you are displaying the pieces
of the transport bar that you want.