You need to attach a volume into /mnt/graphs that contains at least a virtuoso.ini configuration file.
docker pull zorino/docker-virtuoso
docker run --name myvirtuoso -p 9000:9000 -v ./data:/mnt/graphs/ zorino/docker-virtuoso
To load triples from cmd line, create a raw_data folder inside your volume (/mnt/graphs/raw_data), put you raw triple files inside it (*.nq, *.nt,..) and execute the vt-utils CLI.
docker exec myvirtuoso vt-utils load '/mnt/graphs/raw_data' 'http://mygraph.org'
For other commands :
docker exec myvirtuoso vt-utils
vt-utils : virtuoso utilities cmd line
load [dir] [graph] load graph files from [dir] volume into [graph]
fast-load [dir] [graph] load graph files from /mnt/graphs/raw_data volume into graph
with indexing disabled, will reindex after the loading
fct-install install faceted browser (fct) vad
fct-index launch the fct indexing and ranking
delete [graph] will delete graph from the triplestore
help print this