In v0.6.0 the bin/janusgraph-server.sh start script does not start Cassandra any more. Are you sure you did start Cassandra ("cassandra/bin/cassandra") before starting JanusGraph? Also check whether you did not mix up the graph1 and graph1_config graph.graphname values.
I guess you found out to do (before running bin/janusgraph-server.sh): export JANUSGRAPH_YAML=conf/gremlin-server/gremlin-server-configuration.yaml
