How to display UnityEvent widget on custom editor

I need to display a unity event widget on a custom editor, cause i am making the editor for my state machine script. I have looked up the internet on the past few days and apparently the way to do this is with EditorGUILayot.PropertyFiel(), on the OnGUI() method.

Code (CSharp):

1.  void OnGUI()
2.     {
3.                  FiniteStateMachine stateMachine = Selection.activeGameObject.GetComponent<FiniteStateMachine>();
4.  
5.         SerializedObject serializedObject = new UnityEditor.SerializedObject(stateMachine.states[0]);
6.         serializedObject.Update();
7.         EditorGUILayout.PropertyField(serializedObject.FindProperty("action"), true);
8.         serializedObject.ApplyModifiedProperties();
9.     }

the problem is that this causes the event to show as this weird list (wich is usable, but not suitable for my project) like the one in this picture:


and I wanted to know how to show the "regular" nicely formated event widget, like the one in this picture: