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