Filter out other character after the genotype
Using sed:

sed 's,\([01][/|][01]\):[^ ]*,\1,g' file
#    ^  ^               ^     ^  ^   
#    |  |               |     |  *--- applies to all found pattern
#    |  |               |     *------ print the content inside the parenthesis
#    |  |               *------------ any character except a space
#    |  *---------------------------- the pattern to be kept
#    *------------------------------- substitution


You also may want to format the output using column command:

sed 's,\([01][/|][01]\):[^ ]*,\1,g' file | column -t
#CHROM  POS     ID  REF   ALT   FATHER  MOTHER  DAUGHTER1  DAUGHTER2  DAUGHTER3   SON1  SON2
1       736689  .   T     A     0/0     1/0     0|0        0|1        0|1        0|0   0|1
1       758663  .   CGCC  TTAG  0/0     0/1     0|0        0|1        0|1        0|0   0|1


Note the comma separators in the sed command can replaced with other characters typically "/"