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