Just add an underscore and a miner name for each miner

e.g. the graph above is generated with the login username in the miner software for each miner differentiated thus:

1LnUhyCuejMR9dpV559CauwokCGg2n1doH_isengard63
1LnUhyCuejMR9dpV559CauwokCGg2n1doH_AX007202
1LnUhyCuejMR9dpV559CauwokCGg2n1doH_AX002901
1LnUhyCuejMR9dpV559CauwokCGg2n1doH_AX007267
1LnUhyCuejMR9dpV559CauwokCGg2n1doH_AX007341
etc
etc
etc