No - the symbol for DE9 cannot have any different labeling except
for 1-9 because it's a universal part. It can be used for anything,
not only for serial port.
"Unless you like to have the symbol reflect the physical layout"
You seem to be ignoring the fact that the male and female connectors
have pin 1 at different locations. If your symbol happens to reflect
the PHYSICAL layout of the part, you have to have two of them, with at
least different pin numberings.
To illustrate this, I've uploaded sample DE9F and DE9M symbols to
gedasymbols. http://www.gedasymbols.org/user/dj_delorie/