how to avoid overlapping edge and node when using graphviz?

Question

As title,I want to draw an image of ELF file format.The ELF Header has offset of program headers table and section headers table,so I want to use two arrows pointer to point out the relationship.But the edges overlap the node(record) even after I have overlap=false and splines=true set.I have search for a while,but my situation is that the arrows somewhat point to parts of itself.

Following is the dot file I am using to generate the png file.

digraph g {
//margin="1"
overlap='scale'
graph [rankdir="LR"]

"ELF File" [
label="<f0> ELF Header\n e_shoff=0x118| <f1> Program Headers Table | <f2> .text | <f3> .data | <f4> .rodata| <f5> .comment | <f6> .shstrtab | <f8> .symtab | <f9> .rel.text | <f7> Section Table"
shape="record"
];

"ELF File":f0 -> "ELF File":f1 [label="e_phoffset"]
"ELF File":f0 -> "ELF File":f7 [label="e_shoff"]
}