Hi Ani,
Thanks for contacting Syncfusion support.
Please note that, the Diagram and the Chart are two different controls. So, we can't create a single image with diagram and chart. However, we have modified the sample and created the image with chart and diagram. To achieve your requirement, we suggest you to merge both images of diagram and chart. Please refer to the below modified sample.
Sample:
Regards,
Naganathan K G