WordPress multisite Image not showing after moving to NGINX

Recently I moved my WordPress multisite Apache to NGINX server and after moving I see images are not loading. Image location like

http://domain.com/files/2014/02/cfnbanner.png

Code (markup):

My NGINX config file is

log_format main '$remote_addr - $remote_user [$time_local] "$request" ''$status $body_bytes_sent "$http_referer" ''"$http_user_agent" "$http_x_forwarded_for"';
access_log /var/log/nginx/access.log main;
sendfile on;#tcp_nopush on;
keepalive_timeout 65;
#gzip on;
include /etc/nginx/conf.d/*.conf;
server_names_hash_bucket_size 128;
server {
server_name domain.net www.domain.net;
listen 18.199.30.57;
root /home/domain/public_html;
index index.php;
access_log /var/log/virtualmin/domain.net_access_log;
error_log /var/log/virtualmin/domain.net_error_log;
fastcgi_param GATEWAY_INTERFACE CGI/1.1;
fastcgi_param SERVER_SOFTWARE nginx;
fastcgi_param QUERY_STRING $query_string;
fastcgi_param REQUEST_METHOD $request_method;
fastcgi_param CONTENT_TYPE $content_type;
fastcgi_param CONTENT_LENGTH $content_length;
fastcgi_param SCRIPT_FILENAME /home/domain/public_html$fastcgi_script_name;
fastcgi_param SCRIPT_NAME $fastcgi_script_name;
fastcgi_param REQUEST_URI $request_uri;
fastcgi_param DOCUMENT_URI $document_uri;
fastcgi_param DOCUMENT_ROOT /home/domain/public_html;
fastcgi_param SERVER_PROTOCOL $server_protocol;
fastcgi_param REMOTE_ADDR $remote_addr;
fastcgi_param REMOTE_PORT $remote_port;
fastcgi_param SERVER_ADDR $server_addr;
fastcgi_param SERVER_PORT $server_port;
fastcgi_param SERVER_NAME $server_name;
location ~ \.php$ {
try_files $uri =404;
fastcgi_pass unix:/var/php-nginx/141685709813813.sock/socket;
}
location / {
try_files $uri $uri/ /index.php?q=$uri&$args;
}
listen 18.199.30.57:443 default ssl;
ssl_certificate /home/domain/ssl.cert;
ssl_certificate_key /home/domain/ssl.key;
}
}

Code (markup):

Can any on please give me a clue what I am missing in config and why my image are not showing?