Flip Character to face left if moving left?

Hello. So I am trying to get it so that when my character moves left the character will also face left since that’s how someone would walk forward. How would I go abouts by doing this?

using UnityEngine;
using System.Collections;

public class Move : MonoBehaviour
{
	public float speed = 5f;
	private bool mouseDown = false;
	public void OnMouseDown ()
	{
		mouseDown = true;
	}
	public void OnMouseUp()
	{
		mouseDown = false;
	}
	
	public void Update()
	{
		if(mouseDown){
			transform.position += Vector3.left * speed * Time.deltaTime;
			transform.Rotate(-90f, 180f, 0f);
		}
	}
}

Just invert the scale.

transform.localScale = new Vector3(-transform.localScale.x, transform.localScale.y, transform.localScale.z);