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