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