Here’s a video of the circuit in action:
The transistor I used in this video is a BC557 PNP transistor. It’s one of the transistors that James Lewis recommends in his article on the best 4 transistors to keep in your parts kit.
The photoresistor I used has about 10 kΩ when it’s light and 1 MΩ when it’s dark. The resistor on the base of the transistor is a 100 kΩ resistor. The LED is a standard output LED. And the resistor in series with the LED is a 470 Ω.