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