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