If you're connected to the network directly (through a modem), you may just need to add a new rule to System Prefrences > Sharing > Firewall that lets that port through (or turn the Firewall off temporarily just to see whether that's the problem).
If you're connecting via a router you may need to also configure the router's firewall and port forwarding settings to allow that traffic through to your Mac.
What part of the site are you trying to access? - it loads fine for me without that port open..
If you're connecting via a router you may need to also configure the router's firewall and port forwarding settings to allow that traffic through to your Mac.