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