Hi Rahul,
As we said earlier, the issue is not related to diagram component. Could you please confirm us whether you set the parent div height and width in percentage or in pixel. If set in pixel means then split the div in percentage. For e.g. For first div set as 20% , 2nd div as 60% and for 3rd div set as 20%. So that all div gets fit to the window screen.
Regards
Aravind Ravi