You cannot play Versus mode in Left 4 Dead without an Xbox Live subscription. Here is why:
Versus is a competitive multiplayer mode pitting human Survivors against human-controlled Special Infected. This gameplay fundamentally requires an online connection to match players together.
On Xbox consoles, Xbox Live (now Xbox Network) is the exclusive platform for online multiplayer gaming. Left 4 Dead relies entirely on this service for Versus matchmaking.
The game does not support offline Versus play, system link, or splitscreen for this mode. However, you can still enjoy the game locally in these ways:
To experience the competitive thrill of Versus, an active Xbox Live Gold (or Game Pass Core) subscription is mandatory.