Rick,
"ds graphics / width=480px height=400px;"
Should be
"ods graphics / width=480px height=400px;"

And VBARPARM also could do the same thing:

proc sgpanel data=Have noautolegend;
styleattrs datacolors=(CX6f6db2 CXe18dac CXe9ef7a) datacontrastcolors=(CX6f6db2 CXe18dac CXe9ef7a); /* colors of original graph */
panelby Category / novarname layout=columnlattice columns=4;
vbarparm category= Group response=Mean /transparency=0.5 group=Group groupdisplay=cluster
limitlower=lower limitupper=upper limitattrs=(color=black);
colaxis grid display=(nolabel) fitpolicy=rotate;
rowaxis grid display=(nolabel);
run;