As of this moment, access to SharePoint endpoint via Graph API is possible only through the beta endpoint.
Your URL should be as below:
https://graph.microsoft.com/beta/sites/tenantname.sharepoint.com/lists
Make a normal GET call to the above endpoint, the output would be as below:

Reference - Working with SharePoint sites in Microsoft Graph
To access the http://<my_tenant>/site/_api/lists endpoint, Graph API token wont work.
If you are logged into SharePoint you don't need any token at all to make a get request (pure client-side solution). When you make the below call, it gets the data based on your permissions.
$.ajax({
url: "https://sitecollectionurl/_api/web/lists",
method: "GET",
headers: { "Accept": "application/json; odata=verbose" },
success: function (data) {
console.log(data);
},
error: function (data) {
console.log("sowmthing went wrong: "+ data);
}
});
Also, you can use the excellent Graph explorer to test your Graph API calls.
Here, select the version as beta and you can see the data from your sharepoint lists.
Graph Explorer
authentication.asmxsoap endpoint which hasloginmethod, which returns a access token that can be further used while session lasts. Will that help?from zeep import Clientclient = Client('https://<mysite>.sharepoint.com/_vti_bin/authentication.asmx?WSDL')client.service.Login(username='<my_user>@<mysite>.onmicrosoft.com', password='<my password>') returns: { 'CookieName': None, 'ErrorCode': 'PasswordNotMatch', 'TimeoutSeconds': 0 } And I have checked and double checked that the credentials are correct.