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