The European XFEL can generate extremely intense, ultra-short X-ray pulses at MHz repetition rates. Single-crystal CVD diamond detectors have been used to transparently measure the photon beam position and pulse intensity. The diamond itself can withstand the power of the beam, but the surface electrodes can be damaged since a single pulse can already exceed the damage threshold of the electrode material. Presented in this work are pulse intensity and position measurements obtained at the European XFEL using a new type of all-carbon single-crystal diamond detector developed at Diamond Light Source. Instead of traditional surface metallisation, the detector uses laser-written graphitic electrodes buried within the bulk diamond. There is no metallisation in the XFEL X-ray beam path that could be damaged by the beam. The results obtained from a prototype detector are presented, capable of measuring the intensity and 1-dimensional X-ray beam position of individual XFEL pulses. These successful measurements demonstrate the feasibility of all-carbon diagnostic detectors for XFEL use.