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