One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,4)(6,11)(7,9)(13,14,19,17)(15,16,20,18)(23,27)(26,28)(2,3)(5,6,10,11)(7,8,9,12)(13,15)(14,18)(16,17)(19,20)(22,25)(26,28)(2,3)(5,7,10,9)(6,12,11,8)(13,16,19,18)(14,20,17,15)(21,22)(23,26)(24,25)(27,28)(1,3,4,2)(5,8,10,12)(6,7,11,9)(13,17,19,14)(15,16,20,18)(5,9,10,7)(6,12,11,8)(13,18,19,16)(14,20,17,15)(21,23,24,27)(22,26,25,28)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.