FLC MISINTERPRETED A DEP SID AND FAILED TO MAKE A REQUIRED TURN.

Narrative

OUR CLRNC OUT OF PHX WAS 'THE DRYHEAT 2' TO DRYHEAT J74-TRW-TUL; I ENTERED THIS IN THE FMC AN DOUBLE-CHKED IT WITH THE FILED RTE. LOOKING AT THE DEP CHART IS WHERE I MADE THE MISTAKE. SINCE WE WERE GIVEN DRYHEAT INTXN IN THE CLRNC; THIS SOUNDED LIKE A DEP TRANSITION. ON THE CHART IT DEPICTS THE 070 DEG RADIAL OFF OF PXR TO BAYTA; CHOPR; AND SO ON. THIS RADIAL COINCIDES WITH THE 075 DEG HDG OFF OF RWY 7L AT 4 DME. THE CHART ALSO SHOWS A 100 DEG HDG VECTOR AT 4 DME AS WELL. I MISTAKENLY THOUGHT THAT THE 100 DEG VECTOR WAS A SEPARATE TRANSITION AND SINCE WE HAD BEEN CLRED TO DRYHEAT INTXN; I INTERCEPTED THE 070 DEG RADIAL AND FLEW OUTBOUND. DEP QUESTIONED US AT THIS POINT AND THEN CLRED US TO BAYTA ON COURSE BUT ASKED US TO CALL THEM. THERE WERE NOT ANY ACFT CLOSE BY AND WE CREATED NO CONFLICT. ONE OTHER THING. COMPANY HAD DEPARTED AHEAD OF US AND TWR HAD GIVEN US THE FOLLOWING: 'COMPANY AHEAD WILL BE TURNING SBOUND; MAINTAIN VISUAL WITH HIM; CLRED FOR TKOF.' THIS REINFORCED MY BELIEF THAT WE WERE GOING TO BE ON DIFFERENT TRANSITIONS AND DIVERGING AT THE 4 DME POINT. THE BLAME IS SQUARELY ON MY SHOULDERS FOR NOT THOROUGHLY READING ALL OF THE TEXTUAL PROC. I DO; HOWEVER; THINK THE CHART NEEDS TO BE IMPROVED SO THAT THERE IS A MORE DEFINITE SEPARATION BTWN THE INITIAL HEADINGS AND THE 070 DEG RADIAL. IF THERE WAS MORE OF A BREAK ON THE CHART THERE WOULD HAVE BEEN NO CONFUSION ON MY PART.