Here's a breakdown of the phrase and some possible completions:
* No puede mentir: This means "he/she can't lie."
* Porque se le nota en la: This means "because it shows in his/her..."
Possible completions:
* ... cara: "... face." (He/She can't lie because it shows on his/her face.)
* ... mirada: "... gaze." (He/She can't lie because it shows in his/her gaze.)
* ... voz: "... voice." (He/She can't lie because it shows in his/her voice.)
* ... manera de actuar: "... way of acting." (He/She can't lie because it shows in his/her way of acting.)
So, depending on the context, the translation could be:
* "He/She can't lie because it shows on his/her face."
* "He/She can't lie because it shows in his/her gaze."
* "He/She can't lie because it shows in his/her voice."
* "He/She can't lie because it shows in his/her way of acting."
Let me know if you have the full sentence, and I can provide a more precise translation.