Problem with DIY fuzz stompbox FX pedal
After just a quick check, there appears to be one difference between the picture with the physical layout and your schematic, and it's in the input plug. Check these issues please:


No mismatch between input and output? Input: Three-contact connector (tip, ring, sleeve); Output: Two-contact connector (tip and sleeve only) Here's how to tell: The input is the one that goes to the transistor's base via C1; the output is the one that's taken off the potentiometer's wiper.
No mismatch between tip and ring at the input connector? Here's how it's supposed to work: The (hot end of the) signal is found on the plug's tip. This is the one that needs to go to C1 and the base. You are using a "mono" plug on an ordinary guitar cable (no ring, tip and sleeve only!). When you plug the cable into the input connector, you connect the ring and sleeve contacts via the plug, and the battery (-) is thereby connected to the circuit; your plug acts as the "on" switch for the pedal when it is plugged into the pedal.


Also, the diode appears to be inserted with the wrong polarity. With the cathode connected to the base, the transistor is always forward-biased (a lot!), and saturates even without a signal being applied.

A side-note: This is about the most basic design you can have for a fuzz pedal. While there are more fancy designs, the whole point of a fuzz pedal is distortion, so this needn't be a flaw. In terms of fuzz pedal speak, a design that just drives a transistor into hard saturation will be somewhere between the aesthetic triangle of thrash metal, brutal noize and industrial-strength destruction noizze buzz. The reason is that a single bipolar tranistor tends to clip hard and produces a wide spectrum of harmonics once it's overdriven.