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