agreed of dia, tgif, xfig. we also got graphviz. but the question was ?
"Is there any software that automatically make a line diagram or diagram for current local network infrastructure"
looks like you gave the butter but took the bread away or burnt the bread in the process of baking it.
how will you know about the network?
you may use cheop-ng or nmap for LAN or other network asset discovery protocol and oslrp for wireless protocol. how will you do an asset inventory list?
hehe. hope this helps.