Tool to show DNA sequence and allowing upload of own graph data
You can use UCSC genome browser, which supports custom genome sequence and annotation. Specifically, one needs to create a Track Hub to hold genomes and annotations. 

Here is an example: 


  http://genome.ucsc.edu/cgi-bin/hgTracks?hubUrl=http://zlab-trackhub.umassmed.edu/yfu/insects/hub.txt&amp;db=hub_129615_cl_v0.8.2


And here is the corresponding hub.txt file holding the metadata, and URLs to actual fasta, bigWig and bigBed files.