The internal dealing with URL make routing.openstreetmap.de unable to use.
MyConfig = osrm.RequestConfig("routing.openstreetmap.de/routed-foot/route/v1/driving")
But try to access to /route/v1/driving/polyline.
import osrm
MyConfig = osrm.RequestConfig("routing.openstreetmap.de/routed-foot/route/v1/driving")
result = osrm.simple_route([-3.7692, 40.4313], [-3.7420, 40.4183], url_config=MyConfig)