For SAS 9.2, you have to be a little creative. For SAS 9.3, there will be an option to get side-by-side groups in SGPLOT. In the meantime, try this example below. Your group variable will go on the PANELBY statement. There are other options on the PANELBY statement to move the column headings (columnheaderpos) and to remove the label part of the column heading (novarlabel).
Hope this helps,
proc sgpanel data=sashelp.class;
panelby sex / layout=columnlattice onepanel noborder;
vbar age / response=height;