One vertex per element, one color per generator, with an edge from x to x·s.
(1,2,3,4)(5,6,10,12)(7,8,9,11)(13,14,19,18)(15,16,20,17)(23,27)(26,28)(5,7,10,9)(6,11,12,8)(13,15)(14,17)(16,18)(19,20)(22,25)(26,28)(6,12)(7,9)(13,16,19,17)(14,20,18,15)(21,22)(23,26)(24,25)(27,28)(1,2)(3,4)(5,8,10,11)(6,7,12,9)(13,17,19,16)(14,20,18,15)(5,9,10,7)(6,11,12,8)(13,18,19,14)(15,16,20,17)(21,23)(22,26)(24,27)(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.